Darwinian Design - Survival of the fittest spacecraft

Darwinian Design

Survival of the Fittest Spacecraft

April 7, 1999: If two space scientists
have their way, the term "mother ship" will take on
a whole new meaning.

Presenting a paper at the International Conference on Advanced
Propulsion held in Huntsville, Ala., Drs. David Noever and Subbiah
Baskaran, both of the NASA Marshall Space Sciences Laboratory,
discussed the potential of spacecraft reproduction and evolution.

"The next generation of spacecraft will more than likely
evolve traits that their parent-ships could not have equaled,"
says Noever.

Computers can create infinite lists of combinations to try
to solve a particular problem, a process called "soft-computing."
But you don't want a computer to endlessly spew out random lists
of possibilities. Instead, by breeding the most successful operations,
the following generations can learn from past mistakes and successively
improve. This process shares some features with the biological
concept of natural selection, in which the most able organisms
survive in the face of environmental pressure and multiply. Survival
of the fittest, when applied to computer design, is one of the
ingredients for artificial intelligence.

"What it boils down to is trying to get
computers to recognize patterns and react," says Noever.
"We treat the designing choices of a mission like a biologist
treats a genetic chromosome. We can cut and splice missions together
with remarkable speed, compete them against each other, and then
multiply the survivors."

The "survivors" are those who successfully
meet mission goals. Applying natural selection to computer spacecraft
design could generate new possibilities for developing better,
faster and cheaper spacecraft.

A pattern-recognizing computer, for example, could determine
whether plastic parts could safely and effectively be substituted
for military-grade, space-hardened ceramics. Such a substitution
would save money, because plastic parts are 10 times cheaper
to produce than high-tech ceramics.

NASA has been developing spacecraft with
artificial intelligence capabilities. The Mars Pathfinder, the
Earth Observer, and the Deep Space 1 Interplanetary Probe are
just some of the most recent applications of this technology.
Deep Space 1 is especially interesting to Noever and Baskaran,
because it is the first major spacecraft that is expected to
learn during its long, lonely trip through the solar system.

Other Propulsion
Stories this week

Apr 6: Ion Propulsion -- 50 Years in the Making
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The concept of ion propulsion,
currently being demonstrated on the Deep Space 1 mission, goes
back to the very beginning of NASA and beyond. April
6:
Far
Out Space Propulsion Conference Blasts Off - Atoms locked in snow, a teaspoon from the heart
of the sun, and the stuff that drives a starship will be on the
agenda of an advanced space propulsion conference that opens
today in Huntsville.April 7: Darwinian
Design - Survival of
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tickets for space? - Scientists
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discussion at the 1999 Advanced Propulsion Research WorkshopApril 12: Reaching
for the stars - Scientists
examine using antimatter and fusion to propel future spacecraft.April 16:
Riding
the Highways of Light - Science
mimics science fiction as a Rensselaer Professor builds and tests
a working model flying disc. The disc, or "Lightcraft,"
is an early prototype for Earth-friendly spacecraft of the future.Â

Left: An artist's concept of Deep Space 1
traveling using ion propulsion, one of the 12 new technologies
that are being tested during the mission.

"You just have to figure there's some study time for
these kinds of long-term missions," says Noever.

But after a while, the craft will have read through all of
its 'books' and there will be nothing left to study. And those
books will become outdated long before the spacecraft completes
its mission. Earth-based signals can be sent to the craft to
update its library, however. Just as you can download program
updates off the Internet for your computer, scientists can send
new software and new hardware configurations to the distant spacecraft.
In this way, the spacecraft can continue its education via correspondence
course.

"One surprise in developing this technology was the amount
of elbow-room we have to generate improvements," says Noever.

By sending the spacecraft new information, improvements can
be made in on-board memory, bandwidth, power and control features,
and flight software codes. This earth-to-spacecraft link works
two ways, so scientists can download the spacecraft's 'homework'
and use it to design better spacecraft.

Body by Nature, Spacecraft by NASA

Nature has been evolving for millions of years, fine-tuning
and improving its designs through the process of natural selection.
Scientists are looking toward nature to improve spacecraft design,
so the results of Earthly evolution may someday find themselves
having to adapt to other worlds as well.

For instance, the common dandelion evolved to aptly handle
problems in redundancy and navigation. Just as dandelion seeds
float away and plant themselves far from the source flower, the
'dandelion' spacecraft would have a pod land on a planet and
explode with thousands of tiny rovers. That way, if something disastrous
happened to one of the 'seedlings' there would still be many
left to carry on the mission. The mini-rovers would improve on
the dandelion design because they would each have their own 'thinking'
capacity and would be able to communicate with one another while
they're off exploring on their own. Other such 'designed by nature'
spacecraft will probably have superior capabilities in navigation,
power, and communication.

Noever and Baskaran presented their paper, "Darwinian
Spacecraft: Soft Computing Strategies and the Breeding of Better,
Faster, Cheaper Missions," at the Tenth Annual International
Conference on Advanced Propulsion. The conference runs from April
5th through the 8th at the Bevill Conference Center Hotel in
Huntsville, and combines researchers from Marshall Space Flight
Center, the Jet Propulsion Laboratory in Pasadena, Calif., and
the American Institute of Aeronautics and Astronautics (AIAA).